Refrigeration



Nov 20. 1945.

w. H. KITTO REFRIGERATION Filed Nov. 5, 1938 3 Sheets-Sheet 1 INVENTOR h/illiamff. Kilio ATTORNEY W. H. KITTO REFRIGERATION Nov. 20, 1945.,

, 1958 3 Sheets-Sheet 2 Filed Nov.

INQVEPIITOITR William H. mm

ATTORNEY Nov. 20, 1945. w. H. KlTTO I 2,389,317

REFRIGERATION Filed Nov. s, 1958 3 Sheets-Shet s v INVENTOR William H. mm

ATTORNEY Patented Nov. 20, 19a

poratlon of Ohio Application November 3, 1938, Serial No. 238,575

28 @laims. (Cl. 62-1085) This invention relates to refrigeration and more particularly to an ice tray for a domestic refrigerator.

It has been customary in the past to release ice cubes from the freezing tray of a domestic refrigerator by first running hot water over the bottom of the tray to release'the grid assembly and attached cubes from the tray and then running additicnal hot water over the grid assembly to remove the individual cubes therefrom.

This results in the wasting of a considerable portion of the ice since the cubes are materially reduced in size by melting them loose. In addition, the surface of the cubes are cold, wet and slippery and consequently hard to handle.

Water poured over the tray and cubes drips and splashe about over the place where the'cubes are released necessitating wiping up after each removal of the cubes.

It has also been proposed to release cubes from the freezing tray of a domestic refrigerator by mechanical leverage mechanism which first releases thegrid assembly and attached cubes from the'tray and then the individual cubes from the grid assembly. These mechanical devices have not been entirely satisfactory because of .the excessive force necessary to be applied, their complexity and their high cost of manufacture.

In all these prior methods it was necessary to handle the cold tray and cubes at least twice since the grid assembly and attached cubes had first to be removed from the tray and then the individual cubes released from the grid assembly.

In these prior methods it was also necessary to remove all the cubes simultaneously and if only a few were needed, the remainder had to be stored in a cold place or thrown away.

It is accordingly an object of thisinvention to provide an ice tray which eliminates the defects of these prior methods It is another object of this invention to provide an ice tray in which it is unnecessary to first remove the grid assembly and attached cubes from the tray and thereafter the individual-cubes from the grid assembly.

It is another object of this invention to provide an ice tray in which automatic means is permanently associated with the tray for removing the cubes from the tray.

It is another object of this invention to provide an ice tray in which one or more cubes may be removed as desired. I

It is another object of this invention to provide an ice tray in which it is not necessary to apply manual force to remove the cubes from the tray.

' vldual cubes from the tray upon a rise in temperature so that it is only necessary to place the tray in awarm place for a short time insumcient in length to melt the cubes inorder to, remove the individual cubes from the tray.

Other objects and advantages of the invention will become apparent as the description proceeds y when taken in connection with the accompanyme drawings in which:

Figure 1 is a perspective view of one embodiment of the invention partly broken away to show the cube release mechanism; a

Figure 2 is a sectional view of a portion or the device of Figure l depicting an ice cube in released position.

Figure 3 is a sectional view of another embodiment of the invention;

Figure 4 is a sectional view of still another embodiment of the invention on line ti of Figure 5;

Figure 5 is a sectional view of the device of Figure 4 on line Eb of Figure 4;

Figure 6 is a sectional view on line BB of Figure 5;

Figure '7 is a sectional view similar to Figure 6 showing the operating mechanism in raised position;

Figure 8 is a longitudinal section of another embodiment of the invention taken on line 98 oi'FigureQ;

Figure 9 is a cross sectional view of the device of Figure 8 and Figure 10 is a cross sectional view of the device of Figure 8 taken on line iB-W of Figure 8.

The invention of Figure 1 comprises an ice tray generally indicated at I 0. The tray lid is made up of a frame member ii and a plurality of water receiving pockets or ice molds B5. The frame H is made up of bottom it, top it and strips M welded therebetween. Top 03 has a plurality of openings to receive the individual pockets l5.

The individual pockets were made up of a thin metallic cup member 06 and a lining member ll of rubber or'other suitable flexible material cemented or otherwise fastened to the interior of the cup member It. The bottom iBof th rubber lining I7 is positioned above the bottom of the cup member ll to provide a sealed chamber it which is charged with methyl chloride or other highly volatile fluid which will expand with a rise in temperature. The volatile fluid is injected into the space ll through a readily scalable opening 20 after the lining member I is bonded in the cup member it.

In operation the pockets II are fllled with water and the tray placed on the evaporator shelf. The methyl chloride being warm, the bottom ll of the lining will be in raised position, but will soon cool sufllciently to contract the methyl chloride so that the bottom II will move downwardly under the weight of water in the pockets ll, long before the water is frozen. After the water is frozen, the tray is removed from the evaporator shelf by any suitable means and placed on the table or other uncooled place. As is well known, the highly volatile fluid in chamber i! will expand considerably upon a rise of only a few degrees in temperature. The temperature of the evaporator is 32 degrees or below, and the room temperature is '70 degrees or above, therefore the volatile fluid in chamber is. will expand in a very short time after removal of the tray from the refrigerator, a sufficient amount to raise the ice from the pocket I! by bulging the bottom it of the lining member ll upwardly as shown in Figure 2.

Methyl chloride and other similar highly volatile fluids have pressure volume temperature characteristics such that a very large force will be exerted on the bottom It of the lining i I upon a rise in temperature of only-a few degrees.

As the volatile fluid in the space it begins to expand, the large force exerted will break the bond between the ice and its pocket after only a very slight movement. When this bond is broken, the force necessary to raise the ice from the pocket will be veryslight so that the volatile fluid can expand rapidly and quickly raise the ice from its pocket. Thus the initial action is the application of a large force and slight movement, and after the ice bond is broken, only a small force is required to raise the ice a considerable distance. It can thus be seen that this device provides a very simple and easy way of releasing the ice from the tray automatically without the exertion of any manual force.

The device of Figure 3 is similar to that .just described with the exception that the sealed space I9 is formed by welding a thin metallic membrane 2| to the interior walls of the pocket I3 slightly above the bottom thereof. The sealed space I! is filled with methyl chloride, as in the embodiment of Figures 1 and 2, and the memetallic membrane 2| is so made as to normally remain in a downwardly flexed position, and when moved upwardly from such position, it will snap back when the pressure is released.

The operation is the same as that described in connection with the embodiment of Figures 1 bellows could be secured to the bottom of the pocket with its upper closed portion in contact with the rubber liner. In this case the Sylphon bellows would be filled with the volatile fluid.

In operation it would be substantially the same as the embodiments previously described with the bellows expanding with a rise in temperature ang bulging the rubber liner upward to eject the cu es.

The embodiment of Figures 4 to 7, inclusive, operates on, the same principle as those previously described except that a linkage mechanism is provided between the expansibie fluid and the ice cubes so that a maximum force is applied to the cubes when the expansible element begins its expansion so as to insure the initial release of the cubes from the walls of the pocket, and is so constructed that thereafter a large movement is applied to the cubes so that the cubes will be readily accessible for removal from the tray.

Welded to the interior bottom of mold 22 is a sealed enclosure 23 formed of two chamber 24 and 25, the upper one of which is tightly sealed by closure member 23. A thermostatic bulb 21 communicates with the interior of chamber 24 and this chamber in turn communicates with chamber 23 through aperture 23. Secured to cover member 23 and extending downwardly into the upper portion of chamber 25 is a Sylphon bellows 23 closed at its lower end and carrying a plunger 30, the upper end of which extends through cover member 23 into a bore 'in a follower plate 3|. An outwardly extending flange 32 is welded or otherwise secured to the top of chamber 25, and riveted to opposite corners of the flange 32 are spacer members 33 for supporting a plate 34. These spacer members 33 are slotted, and pivoted in these slots are cams or pressure transmitting'members 35 which. lie in grooves in the bottom of follower plate 36. The follower plate 33 is pressed downwardly by spring 3'! located between it and plate 34. The plate 34 has an aperture 38 through which the cylindrical portion 39 of the follower plate 38 can pass.

Cemented or otherwise bonded to the interior walls of the pocket 22 is a rubber liner member 40 the bottom of which i intended to rest on plate 34 and the top of projection-39.

and 2 with the exception that the thin metallic membrane 2| will snap to the downward position after the fluid in the space l3, which is in good heat transfer relationship with the evaporator, has cooled to a sufllcient extent to contract the volatile fluid in chamber It. After the tray is removed from the evaporator shelf and placed in a warm place, the volatile fluid will expand and" The cups 22 may, if desired, be positioned in a frame such as that shown at i in Figure 1. In operation the cups 22 are filled with water and placed on the evaporator shelf of the refrigerator. At this time the volatile fluid in the bulb 21 will be in expanded condition so that the lower end of the bellows 29 will be forced upwardly so that both the follower plates 3| and 38 will be in upward position and the bottom of the rubber liner member 40 will be bulged upwardly somewhat. The bulb 21 being in heat conductive relationship with the bottom of the cup member 22, which is resting on the evaporator shelf, will be cooled down in a very short time so that the volatile fluid in the bulb will contract and the lower end of bellows 29 will move to downward position and consequently allow the bottom of the rubber liner 10 to move to the position shown in Figure 4, due to the fact that the spring 31 will press the follower plate 38 downwardly when the pressure on thebellows is released. This will take place long before the water in the cups 22 has been frozen.

After the water-is frozen, the ice mold is removed from the evaporator shelf and placed on a table or other warm place. In a short time the volatile fluid in the bulb 21 will expand and force the bottom of the bellows 29 upwardly. This will force the plunger 30 and follower plate 3| upwardly pivoting the cam or pressure transmitting members 85 about their pivots. As can be seen the pivot and the follower 38 contacts the cams 35 at a point adjacent the pivot. This will cause a great force and small movement to be transmitted to follower plate 36 at the beginning of the movement of the bellows 29. As the movement of the bottom of the bellows progresses upwardly the point of contact between the follower plate 3| and cams 35 moves toward the pivot while the contact between the follower plate 36 and the cams 36 move away from the pivot. The result of this is that, as the action progresses, the force transmitted to the follower plate 36 will decrease while the rate of movement of the follower plate 38 will increase so that at the end of the action of the bellows 29, the follower plate 36 will have maximum movement transmitted thereto and minimum force.

A comparison of Figures 6 and '7 will illustrate the advantageous features of the invention. In Figure 6 the bellows 29 is collapsed. The plate in i in contact with the outer end of earns 35 and the plate 38 is in contact with the upper surface of cams 85 adjacent their pivots. In Figure '7 this position is reversed. In the position shown in Figure 6. a small force on plate3i will transmit a much larger force to plate 36, while. in the position shown in Figure '7 a small movement of plate ill will, cause a much larger movement of plate it.

At the beginning of the movement of the bellows 29 the ice cube adheres tightly to the liner member 60 and a comparatively large force is necessary to release the bond between the cube and the liner member. When the bond is broken only a small force is necessary to raise the cube from its pocket. The action of the cam member between the follower plates 35 and 36 will assure that there is sufficient force at the beginning of the movement of the bellows to release the cubes from the liner member ill and also that the follower member 35 will have sufficiently large movement at the end of the action to raise the cube upwardly out of the pocket 22 so that it is easily accessible for removal.

The embodiment shown in Figures 8, 9 and 10 comprises a metallic tray member ti whose bottom d2 is bent upwardly at a plurality of points, as shown at 33. Secured to the upwardly extending portions 43 by means of screws $5 is a frame it. This frame is a sheet metal stamping and supports a thermostatic bulb it in direct contact with the bottom of the tray Bulb d8 communicates by pipe i! with a Sylphon bellows iH,'the upper end of which is rigidly secured to portion d9 of frame member it. The lower end of bellows $8 is freely movable and has an extension. secured thereto which is pivoted to a crank arm 5! secured to the end of a rotatable shaft 52 mounted in lugs 53 of the frame member.

The shaft 52 carries a plurality of cam 5% which contact with a plurality of lever arms 55 pivoted to lugs 56 on the frame member i l. The levers 55 are arranged in staggered relation, that is, one is pivoted on one side of the tray and the next adjacent on the other side The frame member M has a plurality of depressions to receive two rows of cup-like members 57 arranged in staggered relation so that the cups on one side are above the free end of above the-free endof the other set of levers 55. Pivoted to the free end of each lever 55 is a plunger 58 which slides in an extension 59 in the bottom of each cup member 51. A rubber liner having pocket Bl fitted to the interior of eachcup member 51 is secured to the top of the tray by cover member 62. This cover may be attached to the edges of the tray as by rivets 63.

The cover member 82 has openings over each of the cup members 51.

Bulb 46 is filled with methyl chloride or other highly volatile fluid which will expand when heated. The cam members 54 are arranged in staggered relation on shaft 52 so that the free ends of levers 55 will be raised one after the other when the shaft is rotated. The surface of the cam 54 is so shaped that when the free end of each lever 55 begins to move, it has only a slight movement butconsiderable force may be applied thereto by the application of a small rotating force to the shaft, and as this movement propresses the rate of movement of the free end of the'tray which rests on the evaporator shelf,

wil1 be cooled quickly long before the water-in the pockets 6! has had a chance to freeze so that the volatile fluid in the bulb Mi will contract causing the lower end of the bellows 48 to raise to upper position and rotating the shaft 52 so that the plungers 58 can move to their lowermost position.

When the water in the pockets has become frozen, the tray is removed from the evaporator shef in any suitable manner and placed on a table or other warm place. The volatile fluid in the bulb it; will expand sufficiently to cause the lower end of the bellow 48 to move downwardly and rotate the shaft 52 and cams 5% upon a rise in temperature of only a-few degrees. As this movement-begins, the cam 54 which is arranged to release its cube first will exert a powerful force on its lever 55 to raise the plunger 58 agairit the bottom of the pocket St to release the bond between the cube and the pocket 6!.

As the temperature rises. the volatile fluid continues to expand so that the next cam in sequence operates in the same way to exert a powerful force to release the bond between its cubes and its pocket. In the meantime, the first cam has moved to a position where less force is exerted on the lever 55 but greater movement is imparted thereto. The bond between the first cube and its pocket 65 having been released, only a small force is needed to raise itin its pocket but considerable movement is necessary to raise it to a position where it will be accessible for removal from the pocket. The action just described of the first and second cubes being released is shown in dotted lines at A and B. respectively, of Figure 8.

As the bulb E6 warms up the volatile fiuid therein will continue to expand rotating the cams 5 9 until all of the cubes have been released as just vdescribed. The arrangement of the cams 5% in sequence and the shape as shown in Figure 10 provides a device in which maximum force is applied to release the bond between each cube one set of levers 55 and those on the other are The bulb 56 being in and its pocket one at a time. After the bond has been released so that less force is necessary to move it the rate of movement is increased. This will assure that the bond between each cube and its pocket will be broken and that each cube will be raised to a sunicient extent to be accessible for removal from the pocket.

While in the embodiment of Figures 4 to 7, inclusive, the bellows 29 itself collapses when the fluid expands, the volume of the enclosure 23 increases, and where expansion is used it is intended to include collapse as well as the more conventional enlargement.

From the foregoing it can be seen that this invention provides a device in which a powerful force can be applied for breaking the bond between cubes and their pockets in which no manual force need be applied but it is only necessary to remove the tray from the evaporator shelf and set it in a warm place to release the cubes.

While I have shown but a few embodiments of my invention, it is to be understood that these embodiments are to be taken as illustrative only and not in a limited sense. I do not wish to be limited to the specific structure shown but to inelude all equivaientvariations thereof except as,

limitedby the claims.

I claim:

1. The method of releasing ice from a mold having a plurality of compartments comprising generating a force by the application of heat, initially transmitting said force to ice in one compartment, to break the bond between the ice and its compartment, and thereafter decreasing the force applied to the ice in saidcompartment and increasing the rate of movement of the force transmitting means while transmitting said force to ice-in another compartment.

2. The method of releasing ice from molds comprising generating a force by the application of heat, initially transmitting said force to the ice to break the bond between the ice and mold and thereafter decreasing the force applied to the ice while increasing the rate of movement of the force transmitting means.

3. In combination, an ice mold adapted to be positioned on the evaporator shelf of a domestic refrigerator, and heat responsive means permanently associated with said mold and removable from the evaporator therewith, said means comprising an expansible chamber containing an elastic fluid which expands upon a rise in temperature and being so constructed and arranged that the ice will be raised upwardly in said mold upon a rise in temperature when said mold is removed from the evaporator.

4. In combination, an ice mold adapted to be positioned on the evaporator shelf of a domestic refrigerator, and a confined body of an elastic fluid permanently associated with said mold and removable from the evaporator therewith, said confined body being of such a character and so associated with said mold and said molds being so constructed and arranged that the ice will be raised upwardly in the mold upon a rise in temperature of said confined body when the mold is removed from the evaporator.

5. An ice tray comprising a frame, a plurality of ice molds associated therewith, and means capable of exerting a force upon a rise in temperature, said means being so constructed and arranged as to raise ice cubes upwardly in said molds in succession as the temperature of said means rises.

6. In combination, an ice tray, heat responsive means for creating a force associated with said tray, and leverage mechanism associated with said means for raising ice upwardly in said ice tray, said leverage mechanism being so constructed and arranged as to transmit a maximum force from said force creating means to said cubes at the beginning of the action of said means.

7. An ice tray comprising a frame, a plurality of ice molds associated with said frame, means for exerting a force, upon a rise in temperature, associated with said tray, a shaft positioned to be rotated by said force exerting means, cams on said shaft, pressure transmitting members operated by said cams and means on said pressure transmitting member for raising ice cubes upwardly in said molds, said cams being so constructed and arranged as to exert maximum force on each of said pressure transmitting members at the beginning of the action of said cams and to raise ice cubes upwardly in said molds in succession.

8. An ice tray comprising a frame, ice molds carried by said frame, a flexible bellows containing an expansible fluid on said frame, and means operated by said bellows to move the ice in said molds upwardly relative thereto.

9. An ice tray comprising a frame, ice molds carried by said frame, a flexible bellows containing an expansible fluid on said frame, and means operated by said bellows to raise the icein said molds upwardly relative thereto, said means being so constructed as to exert maximum force on the ice in each mold at the start of its movement.

10. An ice tray comprising a frame, ice molds carried by said frame, a flexible bellows containing an expansible fluid on said frame, and means so constructed as to exert maximum force on the 40 ice in each mold at the start of its movement and to raise the ice in said molds in succession.

11. In combination, an ice tray having a plurality of cube compartments, an expansible member associated therewith, a fluid adapted to expand upon a rise in temperature in said expansible member and means associated with said expansible member so constructed and arranged as to raise ice upwardly in said compartments upon expansion of said fluid, said means being so constructed as to raise cubes in said compartments in succession.

12. In combination, an ice tray having a plurality of cube compartments, an expansible member associated therewith, a fluid in said expansible member, and means associated with said expansible member so constructed and arranged as to raise ice upwardly in said compartments upon expansion of said fluid, said means being so associated with said expansible member as to raise cubes in said compartment in succession and to exert a maximum force at the beginning of the movement of the ice in each compartment.

13 An ice traycomprising a frame, a plurality of ice molds associated with said frame to form an ice tray adapted to be positioned on the evaporator shelf of a domestic refrigerator, and means permanently associated with said tray and removable from the evaporator therewith, said means being capable of exerting a force upon a rise in temperature and being so constructed and arranged as to raise the ice in said molds upwardly therein upon a rise in temperature of said means when the tray is removed from t e evaporator.

14. In combination, an ice tray adapted to be positioned on the evaporator shelf of a domestic refrigerator, and means responsive to a rise in temperature permanently associated with said tray and removable from the evaporator therewith for raising ice upwardly in said tray rela-- tive thereto, said means being so constructed as to exert maximum force in response to a rise in temperature at the beginning of its raising action and to thereafter raise the ice at an accelerated rate. r

15. In combination,- an ice mold adapted to be positioned on the evaporator shelf of a domestic refrigerator, and heat responsive means permanently associated with said mold and removable from the evaporator therewith, said means comprising an expansible chamber containing an elastic fluid which expand upon a rise in temperature, said means being so constructed and arranged that the elastic fluid will remain inactive at the freezing temperature of the substance to be frozen and will expand to move the walls of said chamber at-a higher temperature structed and arranged to transfer heat from an external source to said fluid and said fluid being of such character and being present in such amount as to exert, upon a rise in temperature present under such condition as to change in state when sufficient heat is transmitted thereto upon arise in temperature above'32 degrees F. upon the removal of said mold from said freezin compartment, said pocket forming means and chamber forming means being so'constructed and arranged that the entire bond between the pocket thereof, a force upon said bottom sufllcient to move the same toward the center of said pocket and break'the bond between the walls of said pocket and ice frozen therein.

17. An ice tray, comprising, a structure forming a receptacle for water to be frozen, a structure forming a chamber for a working medium and a volatile working medium sealed within said chamber, said structures having a common wall, said common wall and said structures bein so constructed and arranged and said working medium being present in such amount that at least a portion of said working medium will change in state upon a rise in temperature above 32 degrees F. to effect a release of the entire bond between said receptacle and an ice block frozen thereto.

18. An ice tray comprising, a receptacle for water to be frozen and a' chamber for a volatile fluid, a volatile fluid sealed within said chamber, said receptacle and said chamber being so constructed and arranged and said fluid being charged under said conditions and being present in such amounts that an increase in temperature of said fluid above 32 degrees F. subsequent to the freezing operation will cause said fluid'to effect a release of the entire bond between said receptacle and an ice block frozen thereto.

19. An ice freezing mold for insertion into and removal from the freezing compartment of a domestic refrigerator comprising, means forming a pocket to receive water to be frozen. and

Y means cooperating with the walls of said pocket to form a chamber separated from said pocket by at least a portion of the walls of said pocket and a volatile fluid sealed in said chamber, said second mentioned means being so constructed and arranged as to transmit heat to said fluid when said mold is removed from said freezing walls and an ice block frozen thereto is released by the change in state of said fluid.

20. An ice freezing mold for insertion into and removal from the freezing compartment of a domestic refrigerator comprising, means forming a pocket to receivewater to be frozen; said pocket having a deformable wall, means cooperating with at least a portion of the walls of said pocket to form a chamber and a volatile fluid sealed in "to said fluid when said mold is removed from said freezing compartment, said fluid being of such character and present under such conditions as to change in state when sumcient heat is transmitted thereto upon removal of said mold from said freezing compartment and said fluid being present in such amounts as to exert sumcient force by the change in state thereof upon said deformable wall to flex the same and break the ice bond between the walls of said pocket and an ice block frozen thereto.

21. An ice freezingmold for insertion into and removal from the freezing compartment of a domestic refrigerator comprising, means for a pocket to receive water to be frozen, said pocket having a snap acting deformable wall, means 00- operating with the walls of said pocket to forma chamberand a voltatile fluid sealed in said chamber, said chamber forming means being so constructed and arranged as to transmit heat to J 22. In combination with an ice tray, a flexible diaphragm dividing the interior of the tray into an upper freezing compartment and a lower sealed compartment, and a fluid sealed in said sealed compartment in position to react against the flexible diaphragm, the fluid in said'com partment being expansible atroom temperature sumciently to exert a force upon said diaphragm and break the bond between the ice and the tray.

23. In the operation of an ice tray for use in a domestic refrigerator and having a pocket to receive water to be frozen, a chamber for receiving a volatile fluid, heat conducting flexible wall means between said pocket and chamber and heat conducting wall means between said chamber and an outside source, that improvement which consists in utilizing the 'heat transferred from said outside sourceto said volatile fluid to volatilize said fluid, condensing at least a part of said volatilized fluid on said heat conducting wall means between said pocket and chamber and utilizing both theheat of condensation of said volatile fluid thus produced and the rise pressure due to the volatilization of said fluid to efiect chamber, said fluid being of such character and 24. An ice mold having a flexible partition therein -dividing said mold into an upper'open compartment and a lower sealed compartment; said lower compartment containing a fluid, said fluid being of such character as to always tend to expand upon a rise in temperature and to always tend to contract upon a fall in temperature and being present in such amount and charged under such conditions that a rise in temperature will flex said partition and break ice free of said mold.

25. An ice tray adapted to be placed on the evaporator shelf of a domestic refrigerator, a partition dividing said tray into an open ice comartment and a sealed compartment and a volatile fluid in said sealed compartment, each of said compartments having substantially thesame projected area, the bottom of said tray being made of heat transmitting material and forming the bottom of said sealed compartment, said fluid being of such character and charged under such conditions as to condense at temperatures below the freezing temperature of water andto vaporize at temperatures above the freezing temperature of water, said bottom and said partition being so constructed and arranged as to vaporize said fluid by the transfer of heat through said bottom when the tray is removed from the evaporator shelf and to recondense it on said partition due to ice being in contact therewith in said open compartment soas to utilize the heat of condensation of said fluid in releasing the bond between the ice and the walls of said open compartment.

26. An ice tray, a partition dividing said tray into an open compartment and a sealed compartment and an expansible fluid in said sealed compartment, at least a portion of said partition being made of flexible sheet material, said flexible portion being so constructed and arranged and said fluid being of such character as to always tend to expand upon a rise in temperature and to always tend to contract upon a fall in temperature and being present under such conditions that said flexible portion is flexed to abowed convex position toward said sealed compartment by the contraction of said fluid upon being cooled and is flexed to a bowed convex position toward said open compartment by the expansion of said fluid upon being heated.

2'7. A device of the character described comprising a wall having a pocket formed therein for receiving water to be frozen into a unit of ice, the bottom wall of said pocket being deformable; means cooperating with said bottom to form a chamber; and a body of fluid confined in said chamber in position to react against said deformable bottom wall; said means being constructed and arranged to transfer heat from an external source to said fluid and said fluid being of such character and being present in such amount as to exert, upon a rise in temperature thereof. a force upon said bottom suflioient to move the same toward the center of said pocket, break the bond between the walls of said pocket and ice frozen therein, said bottom wall being normal] urged downwardly.

28. An ice mold comprising a body having a wall structure providing a mold cavity, and a movable bottom therefor operable to release ice from said cavity, the structure providing an expansion chamber for an expan'sible fluid capable of moving said bottom to release ice upon the expansion of said fluid due to rise in temperature and said movable bottom being normally resiliently urged toward non-ice-releasing position. WILLIAM H. KI'I'IO. 

